After Connect this year I tried to post my Ext JS sample database on my demo site and most users were reporting unsupported notes version. I did some digging and it turns out that amongst everything else R9.0.1 has a newer ODS (52) and therefore would not run on a lower than R9.0.1 server/client.
So after much idiocy and locally encrypted stupidity on my part, I did a search around and found/remembered that you can reduce the ODS aaaaaall the way back to 20 by doing this
- File – Application – New Copy
- Name the file .NS4 (backwards compatible to R4 no less)
- Rename the .ns4 as a .nsf
- and it worked !!
Obviously XPages will not work on an R4 server – but by reducing the ODS it make it compatible with the R8.5.x servers
Bizarrely enough it was also quite significantly smaller than the nsf copies I was creating ODS 52
Xomino 
Hi Mark,
other endings like .ns8 should work, too.
or .ns7
or .ns6
…
Good to remind us of this – reverting the ODS by copying the DB has been a life saver for me more than once 😉
Best regards – Michael
yeah .ns8 makes ODS 48 apparently
thanks 🙂
Hi Mark,
You could more easily use the compact -r (or -R) command to revert your database to a lower level
Wim
See this is a good reason why I blog – I know so little I learn from everyone else.
Thank you so much 🙂
It could even be done in LotusScript, using NotesDatabase.CompactWithOptions (“R”) avoiding having to deal with those evil administrator types. (Used the documentation to learn this today on reading the comment.)
You know maybe I should just Blog my stupidity more often – i would learn faster – thanks guys 🙂